add additional input for audiobox 44VSL

Hi

I am using Audiobx 44 VSL and Audition CC.

I have the inputs working on Audiobox but cannot record the audio in Audition.

I had a look at audio channel mapping and see that there are only two inputs: Mic / Inst 1 and Mic / Inst 2.

I have inputs 3 and 4 that need to be recorded.

How do I add additional inputs?

Many thanks

Justin